A waveshaping digital-to-analog converter (DAC) can be used in a communications circuit to create an analog signal that is transmitted on a communications bus. Compared to an analog-based waveshaping circuit, a waveshaping DAC can provide easy configurability and allows low-power operation. However, a conventional waveshaping DAC performs digital-to-analog conversation in discrete steps, which may cause the electromagnetic emission (EME) to violate protocol specifications. A low-pass filter can be used to reduce the amplitude of the high frequency harmonics of a waveshaping DAC, which can reduce the EME of a corresponding communications circuit. However, an extra low-pass filter can occupy additional silicon area and consume additional power.